Yes, I have. It was with Tri-X each time. Like your experience, it was not all the time, occasionally. It has happened both with diluted 1:1 and with undiluted developer.(posted 8804 days ago)Also, with XTOL, I've experimented with storing (as recommended) the straight, undiluted developer for multiple use. A couple of times I've had heavy deposits of "silver" in the bottom of the container, a clear plastic bottle. All this was with Tri-X Pan.
Now I read that TX is the only Kodak film that is not improved by XTOL. Since I don't use the T-grain films ordinarily, I just stopped using XTOL. I figure one of these days I'll shoot a roll of P3200 and give the XTOL another try.
Until then, it's D-76 (Tri-X and Verichrome Pan) and Rodinal for APX 100.
I'm sorry to hear you are having this problem of inconsistency and unreliability, but still there is satisfaction in knowing I'm not alone out here.
So many people like XTOL that I'm still not totally convinced that I didn't somehow cause these problems.